A chemist investigates the I) melting point
II) flammability
III) boiling point
of acetone, a component of fingernail polish
remover. Which is/are physical?
1. II only
2. I and II only
3. II and III only
4. III only
5. I. II and III
6. I and III only
7. I only
8. None of these

answer: atomic mass was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version.

explanation:

originally atomic mass was used to arrange elements on the periodic table from left to right in a row. each column then shows similar properties of elements of a group.

in modern periodic table, the atoms are arranged in increasing atomic number. as atomic number represents the number of protons in an atom which is unique for every atom.